1. Field of the Invention
The present invention relates to electronic gaming devices, and more specifically to electronic gaming devices which adjust payout amounts based on the activity of other gaming devices.
2. Description of the Related Art
In 1997, slot machines installed in U.S. casinos generated greater than ten billion dollars of revenue. With individual machines typically earning between $50 and $150 per day, slot machines can account for well over 50% of a U.S. casino's overall profits. The net profit from slot machine play for a casino generally exceeds the profit from all other casino gaming activities.
The comparatively high profitability of slot machines may be attributed to many factors, such as the low operating cost of slot machines compared to table games, the ability of slot machines to conduct games at a faster play rate compared to table games, the appeal of slot machines to players of every skill level, and the large potential payout offered by slot machines in exchange for a comparatively small wager.
Since the profitability of slot machines is directly proportional to the amount of time that they are played, casinos often attempt to prolong the length of player gambling sessions. Casino slot clubs were developed with just such a goal in mind. Players were provided reward points for each dollar wagered, with points exchangeable for cash, merchandise, food, etc. Much like an airline frequent flyer mile system, slot clubs encouraged greater play since the player would earn larger reward point totals. Although these programs succeeded in providing an incentive to play more, players had no incentive to extend the length of a given gambling session since they could always pick up where they left off at a later session. Three sessions of one hour each were thus equivalent to one session of three hours. Every time that a player ended a gambling session, however, there was a risk that he will go to another casino. For this reason, casinos would prefer that a player play for extended periods of time rather than over multiple sessions.
One method that has been used to motivate increased play of slot machines is to generate bonus payouts dependent on cumulative effects of plays. For example, several reel slot machines manufactured by International Game Technology ("IGT") provide bonuses for the cumulative effects of spins. The game "Red, White and Blue Racing 7s" is representative of such games, featuring a race based on a number of reel symbols obtained within a given time period. The three colors of the reel symbol "7" appear on the reels with different frequencies. When a "7" comes up on a reel, a racing character "7" of the same color advances on an animated track. When a racing character crosses the finish line, the player receives a bonus, with higher bonuses for the symbol colors of lower frequency.
In another example of a cumulative bonus symbol type of game, AC Coin & Slot Service Company developed a series of games in which there was a time period during which a player attempted to accumulate a number of reel symbol outcomes. Three bonus payouts were provided at ten, fifteen and twenty-five coins, respectively. Each reel of the slot machine included one or more special symbols, the occurrence of which advanced the player closer to one of the three bonus levels. Upon the completion of a one-hundred second time period, the bonus session ended and the player result (i.e. the number of special reel symbols accumulated) was compared to the totals required to obtain each bonus level. Any bonus earned was paid out, and any accumulated special reel symbols were then zeroed out.
Slot machine racing games, such as the Red, White and Blue Racing 7s and bonus symbol games of AC Coin encourage an extended length gaming session in that the player does not want to end a session while he is still competing for the bonus payouts. However, the excitement and the motivation last only for the limited period of the race. When the race ends, all player investment in the racing aspects of the game are lost, and the player may be motivated to cease play and search for another game.
Accordingly, a need exists for a slot machine which provides the player with an incentive to stay with the machine for longer periods of time.